is there any way to self human combust on purpose?

Generally spontaneous human combustion is something that still bewilders some, human combustion happens very rarely and doesn't affect the surrounding areas, so unless you want to set your self on fire, human combustion will remain spontaneous and very rare.

The answer is 19 1/2 which is B)

Explanation:

That is because if you multiply 9, 3 1/4, and 2/3 it gives you 39/2 which if you  simplify it is 19 1/2